When a stroke affects the MCA, it usually causes severe paralysis down one side of the body.

The patients had also been given clot-busting drugs, but shown little or no improvement.

Cooling

Ten patients who were cooled were compared with nine who were not.

Those who were cooled were given drugs to paralyse them to prevent shivering. They were also sedated and had breathing tubes inserted.

It took around three and a half hours for the patients to achieve hypothermia, which was defined as 32C for 12 to 72 hours.

Dr Derek Kreiger, who jointly led the research, said: "Hypothermia was well tolerated by most patients and there were no significant differences in minor or critical complications between the two groups."

Cooled patients had lower levels of disability when checked at three months.

On a scale of nought (normal) to six (death), cooled patients averaged 3.1 compared to 4.2 in the non-cooled group.

Three of the cooled patients had died, compared to two of the nine of the other group.

Eoin Redahan of the Stroke Association told BBC News Online: "Unfortunately the care of stroke patients in the UK is not geared up to introduce the American clot busting agents and even less likely to introduce an experimental lowering of brain temperatures.

"We've a long way to go but hopefully UK stroke care will improve in the next 2-3 years with the introduction of the stroke section of the NSF for older people," said